import structure.*;
import com.mw.io.*;

public class BTBuilder {

    public static void display (BinaryTreeNode root) {
        if (root != null) {
           display(root.left());
           display(root.right());
           System.out.print(root.value() + " ");
        }
    }
    
    public static void main (String args[]) {
        ReadStream r = new ReadStream();
        String S;
        BinaryTreeNode t, U, V;
        Stack T = new StackList();
           
        // read data from input and build the tree
        S = r.readString();
        while (!r.eof()) {
           t = new BinaryTreeNode(S);
           if (S.equals("+") || S.equals("-") || S.equals("*") || S.equals("/")) {
              U = (BinaryTreeNode)T.pop();
              V = (BinaryTreeNode)T.pop();
              t.setLeft(V);
              t.setRight(U);
              T.push(t);
           }
           else 
              T.push(t); 
           S = r.readString();
        }
        
        // pop and display the final tree on the stack
        display((BinaryTreeNode)T.pop());
        System.out.println("\nend of run");
        
    }
     
}